Bead releasing and removing head for a tire-fitting machine, for assembling/disassembling a tire

ABSTRACT

Bead releasing and removing head for a tire fitting machine comprising a support frame ( 2 ) anchored to the tire fitting machine and supporting at its top at least a bead releasing disk ( 3 ) and a bead removing tool ( 4 ), having a working tip ( 7 ), wherein the removing tool ( 4 ) is slidably supported by said head and comprises driving means ( 5 ) suitable for displacing it, upon control, so that the working tip ( 7 ) is movable between an advanced working position and a withdrawn rest position.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a bead releasing head providedwith a bead removing tool for assembling/disassembling a tire, to beused on a tire-fitting machine, i.e. a tire assembling/disassemblingmachine.

[0002] As known, tire-fitting machines have a series of tools designedto carry out and assist in operations of tire fitting on, anddisassembling from, wheel-rims.

[0003] For carrying out disassembling operations use is made of a beadreleasing disk or roller designed to act on the tire-beads and of aremoving lever or tool which is inserted between the tire bead and theedge of the wheel-rim, once the bead releasing operation has beencompleted both on the front side and on the back side of the tire, tocause the removal from the wheel-rim first of one side of the tire, andthen of the other.

[0004] It has already been suggested to fit a bead releasing disk orroller D and a removing tool U on one head T mounted for rotation andlockable in position by means of a support arm or upright M, as shown inFIGS. 1 to 4 of the accompanying drawings which show a bifunctionaltool-carrying head T of a known type, in the various bead releasing andremoving stages both at the front and back side of a wheel-rim C fordisassembling a tire P from its respective wheel-rim C.

[0005] The bead releasing disk D and tool U are arranged facing eachother, whereby following a 180° rotation of the head T on its respectivesupport arm or upright M, the disk D or the bead removing tool U can bebrought to its working position, i.e. it can be oriented facing the tireP to be disassembled from its respective wheel-rim C.

[0006] In any case, the tool carrying heads T require that the operatorcarries out quite laborious positioning and setting manoeuvres thatheavily slow down the working steps and entail a certain dexterity thatis acquired only with adequate experience. After each operation, eachtool D, U, at the operator's discretion, should be moved again to therest position; in the real practice, however, such an operation is oftenignored, and thus in the subsequent bead releasing operation it will benecessary for the operator to displace the tools to their correctposition before being able to use them.

[0007] Moreover, after intervention of the bead releasing disk D thathas thus urged the bead Pa of tire P inside an intermediate groove Ca inwheel-rim C through its active edge or front, within the same timeinterval in which one tool D, U is replaced by the other, i.e. to removethe bead releasing disk D and bring the removing tool U to its workingposition, bead Pa of removed tire P tends resiliently to return to itspre-release position, i.e. towards the outer edge Ce of the wheel-rim,thus at least partly obstructing the passage delimited by edge Ca andbead Pa under the action of the bead releasing disk D, thereby makingthe insertion of bead removing tool U much more difficult.

SUMMARY OF THE INVENTION

[0008] The main object of the present invention is to eliminate theabove shortcomings of the state of the art by contriving a beadreleasing head for tire assembling/disassembling machines that makes itpossible to eliminate the need to put the head in position again afterthe operation of a tool, to have the possibility to use the other toolto release the beads and remove the tires from the their respectivewheel-rims, thus making the bead releasing and removing operationssimpler, swifter and more expeditious.

[0009] This and other objects that will be better apparent below areattained by a bead releasing and removing head according to the presentinvention for a tire assembling/disassembling machine, including anupright member anchored to the said tire assembling/disassemblingmachine, and a bead releasing disk and a bead removing tool supported atthe top of said upright member, characterised in that the said beadremoving tool is slidably supported by the said head and comprisesdriving means arranged to cause said bead removing tool to bedisplaceable, upon control, between an outwardly extended workingposition and a withdrawn rest position.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Further aspects and advantages of the present invention will bebetter apparent from the detailed description given below of a preferrednot exclusive embodiment of a bead releasing and removing head for atire disassembling machine shown by way of not limiting example in FIGS.5 to 11 of the accompanying drawings, in which:

[0011] FIGS. 5 to 8 show the same bead releasing and removing steps ofFIGS. 1 to 4 carried out by means of a bead releasing and removing headaccording to the present invention;

[0012]FIG. 9 shows a partly cut-away elevation side view on an enlargedscale of an alternative embodiment of the bead releasing and removinghead shown in FIGS. 5 to 8; and

[0013]FIGS. 10 and 11 show partly cut-away elevation side views on anenlarged scale of two further alternative embodiments of a beadreleasing and removing head according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] With specific reference to FIGS. 5 to 9, reference numeral 1generally designates a bifunctional bead releasing and removing head fora tire fitting-disassembling machine, not shown in the drawings. Head 1comprises a support upright 2 which, for instance, protrudes from theframe of the tire fitting-disassembly machine on which head 1 is to befitted, a bead releasing disk 3, preferably frusto-conical in shape, anda removing tool 4.

[0015] Bead releasing tool 4 is slidably, e.g. telescopically, mountedin a tubular seat 6 provided at the top of upright 2, so as to bedisplaceable between a working position, in which it extends outwardsfrom its respective seat 6 (FIGS. 6 and 8), and a rest position in whichit is withdrawn in it (FIGS. 5 and 7).

[0016] In its working position, the bead releasing tool 4 has its workend or tip 7 facing towards the head portion of the working front 8 ofthe frusto-conical bead releasing disk 3 so as to extend above the disk3 when it is moved to its working position, preferably substantially ona diametrically opposite vertical plane of disk 3 to such an extent asto protrude well beyond the distal work edge or front 8 thereof.

[0017] More particularly, bead releasing tool 4 is usually curved inshape, and thus even the tubular seat 6 is correspondingly curved to actas an optimal support and guide means for the bead releasing tool.

[0018] The upright 2 is provided at the top thereof with an appendix orarm 10 that extends therefrom at an angle with respect to the upright 2.Bead releasing disk 3 is idly rotatably mounted on the arm 10 on an axisof rotation perpendicular to arm 10. Thus, the axis of rotation of beadreleasing disk 3 is inclined at predetermined angles with respect ofboth the upright 2 and the axis of a wheel-rim 101 fitted with a tire100 against which disk 3 is designed to act.

[0019]FIGS. 5 and 6 show the working steps (bead release and beadremoval) carried out by the bead releasing disk 3 and the bead removingtool 4, respectively, on one side of tire 100, whereas FIGS. 7 and 8illustrate the same working steps at the other side of the same tire,after the tool carrying head 1 has been rotated once through 180° aboutits own (vertical) axis.

[0020] As better visible in FIG. 9 that illustrates a head 1 with someconstructional modifications with respect to the head illustrated inFIGS. 5 to 9, at its end opposite to the working end 7 bead removingtool 4 is articulated at 9 to the end of a piston rod 12 of a fluidoperated jack, e.g. a pneumatic double-action jack 5, whose cylinder 15is articulated to the upright 2. Jack 5 is designed to actuate beadremoving tool 4, i.e. to displace it, upon control, to its workingposition, or to withdraw it inside its support and guide seat 6.

[0021] In the embodiment shown in FIG. 9, the arm 10 at the top of theupright 2 is arranged adjacent to the tubular seat 6 of removing tool 4,rather than away from it, as shown in FIGS. 5 to 8.

[0022] In an alternative embodiment, the tubular guiding seat 6comprises (as shown in FIG. 10) two pairs of rollers 16 rotatablymounted on the side opposite to the bead removing tool 4 so as to guideit while the same is being displaced between its working position andits rest position, as explained above.

[0023] The driving means for the bead removing tool 4 can be of anysuitable type. Thus, e.g. they comprise a pinion or spool 17, and a rack18 (as shown in FIG. 11). Rack 18 is preferably formed in a section ofthe outer backside of the bead removing tool 4 (usually convex inshape), whereas pinion 17 is keyed on the output shaft 19 of a motor 20(e.g. an electric motor) supported by the upright 2.

[0024] The operation of a bead releasing and removing head according tothe present invention is the following: when an operator proceeds withdisassembling a tire 100 from a wheel-rim 101, he secures the wheel-rimto a rotary support flange or platform of a tire fitting machine anddeflates tire 100. Then he moves the upright 2 closer to the tire sothat the working edge 8 of the tire releasing disk 3 contacts the bead102 of the tire 100. At that stage the bead removing tool 4 is keptwithdrawn within its seat 6.

[0025] Then the operator sets in rotation the rotary platform of thetire fitting machine, and thus the wheel-rim 101 and tire 100 therewith,whilst the upright 2 is urged towards the wheel-rim. The urging actionexerted by the upright 2, thus by the bead releasing disk 3, causes aprogressive release of the bead 102 along the whole circular edge 103 ofwheel-rim 101, while pushing the tire bead towards a central groove 104of the wheel-rim 101.

[0026] Once the bead has been fully released, the bead removing tool 4is extracted by causing it to slide out from its seat 6, or to slidebetween pins 12, by energizing the linear actuator 5, i.e. by startingmotor 20 that causes pinion 17 in meshing engagement with rack 18 torotate.

[0027] The extraction of bead removing tool 4 occurs in the samedirection and on the same side of the active front 8 of the beadreleasing disk 3 that is held in an urging condition against bead 102,while sliding over and flush with it along a curved path so as toovertake it and move the working end 7 beyond the active front 8 to suchan extent as to be inserted between the edge 103 of the wheel-rim 101and the bead 102 of the tire 100 to engage the inner side of the bead.

[0028] Once the bead removing tool has been fully inserted underneaththe tire bead, the operator causes the upright 2 to be moved away fromthe wheel-rim 101 while setting the flange of the tire fitting machinein rotation at the same time, so as to separate the active front 8 ofthe bead releasing disk 3 from the tire 100, whilst also slightlywithdrawing bead removing tool 4 that can thus progressively remove thebead from wheel-rim 101 to disassemble it therefrom—see FIG. 6.

[0029] The same sequence of operations is also carried out by theoperator on the opposite side of the tire 100, e.g. after the wheel-rim101 lying on the rotating platform of the tire fitting machine has beenturned over, or else after the upright 2 has been displaced and head 1rotated on its own axis through 180°, and repeating the working sequencedescribed above.

[0030] The invention as described above is susceptible to numerousmodifications and variations within the scope of the claims.

[0031] Thus, the bead releasing and removing head was described withparticular reference to disassembling operations of a tire from awheel-rim. It should be understood, however, that, as a person skilledin the art is well aware, by acting in reverse, the assembling of a tireonto the respective wheel-rim can also be carried out in an expedite andaccurate manner.

[0032] In practice a variety of materials and respective shapes andsizes could be used to meet the specific requirements.

[0033] The disclosure in Italian patent application No. VR2001A000124from which priority is claimed is incorporated herein by reference.

[0034] Any reference sign following technical features in any claim hasbeen provided to increase intelligibility of the claim and shall not beconstrued as limiting the scope of the claim.

1. A bead releasing and removing head for a tireassembling/disassembling machine, including an upright structure (2)anchored to the said tire assembling/disassembling machine, a beadreleasing disk (3) and a bead removing tool (4) having a work tip (7)both supported at the top of said upright structure (2), wherein thesaid bead removing tool (4) is slidably supported by the said head andcomprises driving means (5) arranged to cause said bead removing tool(4) to be displaced, upon control, whereby its work tip (7) is movablebetween an outwardly extended working position and a withdrawn restposition.
 2. A bead releasing and removing head according to claim 1,wherein the said work end (7) is displaceable on the same side and inthe same direction as the said bead releasing disk (3), while slidingover and flush with it along a curved path, thereby overtaking the saidbead releasing disk (3) to reach its working position.
 3. A beadreleasing and removing head according to claim 1, wherein in its workingposition, the said work tip end (7) is located above the said beadreleasing disk (3) substantially on a vertical diametrical plane.
 4. Abead releasing and removing head according to claim 1, wherein the saidremoving tool (4) is provided with sliding supporting and guiding means(6, 16, 18).
 5. A bead releasing and removing head according to claim 4,wherein the said support and guide means comprises a curved tubular seat(6) carried by the said support structure (2).
 6. A bead releasing andremoving head according to claim 4, wherein the said support and guidemeans comprises at least two pairs of pins (12) idly mounted on the saidsupport structure (2).
 7. A bead releasing and removing head accordingto claim 1, wherein the said driving means (5) of the said bead removingtool (4) comprise at least one linear actuator (15) carried by the saidsupport structure (2) and in operational engagement with the saidremoving tool (4).
 8. A bead releasing and removing head according toclaim 1, characterised in that the said driving means (5) of the saidbead removing tool (4) comprises a rack (18) formed in a section of thesaid removing tool (4), a pinion (17) in meshing engagement with thesaid rack (18) and a motor (20) for said pinion (17).
 9. A beadreleasing and removing head according to claim 1, characterised in thatthe said bead removing tool (4) is curved.
 10. A bead releasing andremoving head according to claim 1 rotatably mounted about an axis ofrotation on the said support structure (2).